The present invention pertains generally to devices and methods useful for electrical excitation of tissue. More particularly, the present invention pertains to devices and methods useful for the transcutaneous delivery of ions and the electrical stimulation of tissue and cells at targeted areas of the body. The present invention is particularly, but not exclusively, useful for generating negative ions and producing electrical currents in the uveal and periuveal areas of the eyes.
Electrical stimulation of tissue in the major muscle groups such as the arms and legs by externally supplied electrical signals has been shown to relax and strengthen muscle tissue. When used in this way, the externally supplied electrical signals are similar to the electrical signals supplied by the nervous system to contract and relax the muscles. By the exercise of targeted muscles, damage associated with strain, fatigue and overuse can be repaired. Electrical stimulation of tissue is often used as part of a prescribed physical therapy program for this purpose. Further, electrical stimulation of tissue is known to dilate nearby blood vessels, increasing circulation and effectively increasing metabolism and the amount of beneficial oxygen available for targeted tissues such as muscle tissue and nerve tissue.
Additionally, devices have been disclosed which generate ions (negatively or positively charged particles) and release the ions into the air for contact with nearby individuals. Contacting the body with ions is known to produce certain therapeutic results. Specifically, ion generators that produce negative ions have been used with some success to reduce the effects of asthma, allergies and hayfever. Some research also indicates that an environment rich in negative ions may alter brain wave activity thereby reducing depression and anxiety, and increasing alertness. Unfortunately, airborne ions are often ineffective because the exposure level to airborne ions is generally low. Additionally, airborne ions tend to be neutralized quickly after contact with the body, rendering the airborne ions ineffective. Further, the rate at which the airborne ions are neutralized is increased if the body is in contact with an electrical ground. Finally, it is difficult to reach specific tissues and cells in targeted areas of the body with airborne ions. Nevertheless, it may be desirable to target specific areas of the body for ion therapy, electrical stimulation, or both. For purposes of the present invention, both ion therapy and electrical stimulation are considered types of electrical excitation. Examples of areas of the body that may be desirable to target include areas where an increase in circulation may be beneficial. For example, the penis may be targeted in individuals suffering from erectile dysfunction (ED). Another desirable target area may include the sinuses in individuals suffering from allergies, hayfever or asthma. For individuals with ophthalmic deficiencies, the eye and areas surrounding the eye may be targeted.
The muscle tissue, nerve tissue and other cells found in and around the eye are critical for proper eyesight and function. For example, the ciliary muscles of the eye are relied upon to focus on objects by changing the shape of the lens of the eye. Additionally, muscles in and around the eye allow for eyeball movement thereby enabling a person to see in different directions. Smaller muscles within the eye allow the iris to open and close in response to changes in external lighting conditions. Like all muscles, the muscles of the eye are subject to fatigue and strain due to overuse, as well as the effects of aging. If the performance of the eye muscles such as the ciliary muscles become impaired, normal eye function can be adversely affected. For example, it is known that when the performance of the ciliary muscles is impaired, the time required to focus in response to a sudden change in lighting conditions increases substantially. Further, the performance of the retinal cells and the tissues in the optic nerve can affect visual acuity.
In light of the above, it is an object of the present invention to provide devices and methods suitable for the purposes of electrically exciting tissue and other cells in targeted areas of the body. It is another object of the present invention to provide devices capable of generating both negative ions and currents for electrical stimulation in the uveal and periuveal areas of the eye to restore optimal eye function by increasing blood flow and metabolism. It is yet another object of the present invention to provide devices and methods capable of generating pulsed electrical currents and/or time-varying electrical currents in the uveal and periuveal areas of the eye to thereby allow treatments tailored to a particular vision deficiency. It is yet another object of the present invention to provide devices and methods for electrically exciting muscle tissue, nerve tissue and other cells to increase blood flow and available oxygen at target areas within the body. Yet another object of the present invention is to provide devices and methods for electrical excitation of tissue and other cells at target areas in the body which are easy to use, relatively simple to manufacture, and comparatively cost effective.
The present invention is directed to devices and methods for electrically exciting tissue and other cells at target locations within the body. In one embodiment of the present invention, a device is disclosed for use in electrically exciting tissue and other cells in the uveal and periuveal areas of an eye. In this embodiment, the device includes a frame that is very similar to an eyeglass frame in shape and construction. The frame is formed with a bridge section and a pair of supports. Each support has a first end which is affixed to and extends from the bridge section, and a second end which rests upon the ear of the patient. When the frame is positioned on the head of the patient, the bridge section rests against the nose of the patient and each support rests upon one of the patient""s ears. Preferably, the frame is constructed of a flexible plastic material which allows the frame to be slightly expanded during positioning on the patient""s head to thereby afford a snug, stable fit when positioned properly on the patient""s head.
A pair of conductive electrodes is attached to the frame. Preferably, each electrode is disk-shaped and has a circular contact surface. The contact surface can be flat or have a slight curvature and is preferably approximately thirty millimeters (30 mm) in diameter and gold plated. A first electrode is attached to one of the supports and a second electrode is attached to the other support. Each electrode is attached to a support between the end of the support that is affixed to the bridge section and the end of the support that rests on the ear of the patient. Specifically, the electrodes are located on the supports to position the first electrode adjacent the orbit of one eye, while positioning the second electrode adjacent the orbit of the other eye. When the frame is properly positioned on the patient""s head, the contact surface of the first electrode is held against the orbit of one of the patient""s eyes, and similarly, the contact surface of the second electrode is held against the orbit of the patient""s other eye. It is to be appreciated that other frame configurations can be used to hold a pair of electrodes against a different target area such as the sinuses.
A power unit is provided that includes a voltage source for applying a voltage to the electrodes to thereby electrically excite the tissue and other cells in the uveal and periuveal areas of the eyes. Electronic circuitry is provided for allowing the voltage to be applied to the electrodes in two distinct modes (described in detail below). The power unit includes a housing to contain the voltage source and electronic circuitry. The first electrode is electrically connected to the power unit by a first wire, and the second electrode is electrically connected to the power unit by a second wire.
When the power unit is used in the first mode (ion-therapy mode), the patient""s body is isolated from ground (i.e. earth-ground), and the voltage source is used to simultaneously place an equal charge on each electrode. Preferably, a negative charge is placed on each electrode to thereby create beneficial negative ions in the uveal and periuveal areas of each eye. In this first mode, a direct current (DC) voltage source having approximately 200 volts is provided. The positive lead from the voltage source establishes the reference potential of the power unit. The negative lead from the voltage source is then electrically connected to both the first electrode and the second electrode. Consequently, in the first mode, each electrode is maintained at the same potential and no electrical current flows from one electrode to the other. Instead, due to whatever potential differences there may be between the electrodes and the body, current will flow from the electrodes and into the body to create negative ions. Preferably, the electrodes, when positioned on the patient, are charged (i.e. connected to the voltage source) for a period between approximately three minutes and approximately fifteen minutes.
In the second mode (electrical stimulation mode), the voltage source can be used to establish a voltage differential between the first electrode and the second electrode thereby allowing electrical currents to flow from the first electrode, through the uveal and periuveal areas of the eyes, to the second electrode. A voltage differential of up to approximately 5 volts can be applied to the electrodes to stimulate the tissue and other cells in the uveal and periuveal areas of the eyes. Electronic circuitry is provided in the power unit to allow the magnitude of the voltage to be varied over time and/or to allow the voltage to be pulsed. For the present invention, the voltage can be periodically reversed thereby allowing electric current to initially flow from the first electrode to the second electrode and subsequently flow from the second electrode to the first electrode. For certain treatments, the voltage can be configured as a pulse package having a sequence of pulses. The sequence of pulses can be made to increase in a substantially linear manner from a zero voltage to an absolute voltage. The increasing pulses may be followed by a sequence of pulses decreasing from the absolute voltage to zero voltage. For some treatments, the voltage can be configured as a pulse package having a first sequence of pulses and a second sequence of pulses. For the present invention, the polarity of the voltage used for the first sequence of pulses can be reversed for the second sequence of pulses.